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APRIL,1907. MONTHLY WEATHER REVIEW. 175 1901-1905, leaving out the months of 'this depression. These We shall limit ourselves simply to indicating the duration means are presented in the following Table 2. of insolation at Warsaw, and the sums of heat for the three TABLE%-Nan annual summury, bused on actinometric meaccurenlents made consecutive years 1903, 1904, and 1905. (See Table 3 and at Warsaw during 19111-1905, omitting December, 1902- February, 1904. Table 4.) The siims of heat have been calculated" from combined readings of heliographs [sunshine recorders] and 1 la131 4 1616/7 actinometers; they are esprest in gram-calories per square Monthly Q I ntax. centimeter of horizontal surface. Month. 1 mean. I I 30°: menu 1 ,, 1 h 1 distance. f I (2 1 Q 1 T.4BLE 3.-&rfition Of i7~~1okttion(It W~ir8aici. ~~~ ~- --~__ ___ 0 I. ............ ............. O.X?9* 17 1.010 14 3.0 0.937 I1 ...:... .... ............. 1. ox2 25 1.126 12 2. 7* 1.w2 111.. ......... ............ 1.140 36 1.063 1s 3. s 1.354 IV ....................... 1.195 47 1.047 19 5.4 1. J?0 V ......................... I. 164 56 0. Y93 49 7.0 1 .XIj 1903. VI. .......... ............. 1.11s 61 0.944 32 9.1 1.294 19(J4 VII.. ........ ............. 1.173 69 1.008 35 9. 7 1. :j2a 1905. ............... IIX. 9 4%. Y ' i51.6 , 218.6 ~ 1512.9 1'111. ........ ............. 1.119 51 0.975 31 10. 3 1.2tiY i IS.. ......... ............. 1.169 41 1.063 :E Y. 0 1.367 x ............ ........... 1.036 29 1.042 15 6. 8 1.241 SI.. ......... ............. 0.897 20 1.01s 15 1.049 SII.......... ............. 0. S6L 15 ~-1.08s ___7 0. 97s Mean ...... .............. ....... ......... 1.017 278 Winter. qprins. Year. I, 11, SII. 111, IV, v. The monthly means, Q, of the cLiue~nannual sruiiruar~.' ~~ -1- ~ -___# (Tabl.e 2) are represented graphically in curve 111, fig. 2; the v.oil. .rir. wl. !/I.. <VI/, cir. oil. gr. col. ........ 1:;;; ~ llJSl0 . ii3no 7440 36890 curves for each of the consecutive years 1901-1905 are pre- l!W4. ............... 1 Ilil'J0 W61) 815U 5.I230 sented in the same figure by lines that are numbered for the 191J5.. ............ ]!I10 1SiW '27i!IO 5460 , 50920 consecutive years ancl that are based on the data of Talde 1, ~~ ~__~~~~~ ~~ ~ ~ -__ column 2. 7. OILthe inarch (if the tlrpressio)r 'If solar rrrdinticm as ohsrri'ed at TParsnm-By comparing the monthly values of the period December, 1902, to February, 1'304, (see Table 1) with the annual summary, Table 2, it is seen that- (a) The depression is suddenly emphasized in the month of December, 1902, giving at Warsaw from its beginning, a value about 20 per cent lower than those of the mean annual summary. (b) On account of this great depression the whole amiunl march of the intensity of solar radiation in 1903 undergoes :I perturbation which has maskecl, or even changed, the usual variation of radiation, during that year at Warsaw. (c) This depression. persisting from the month of Decem- ber, 1902, until the mouth of February, 1904, inclusive. and giving a .mean diminution of intensity exceeding 15 per cent at Warsaw, has not had a uniform character in its march, but on the contrary has presented several oscillations. (d) After a sharp ancl large diminution in December, 1902, THE " SOUTHWEST" OR "WET " CHINOOK. H. 151 Lhlhl.11 \\I, SI I1.ltt.d LRW'tflU, OLlX , RIdlt h 19, 1907. and after the particularly low values of the intensity in the months of February ancl March, 1W3, a certain weakening of In the minter of IS51 I spent a couple of montlis on Queen this depression is marked tonran2 the beginning of the summer Charlotte Islaud, of? the British dmericm coast, sailing from of 1903; the values for June of that year at Warsaw are rela- Puget Sound on a gold hunting voyage. I t,liink we sailed tively quite high. But in July, ancl in the following months from the Souncl early in January. We went about half-way (I until October the depression very clearly increases up to about should t,hinli) up the island, and enteretl Golcl Harbor (on the 15 per cent. west side). We went east about 12 miles to the head of the (e) The end of 1903, as likewise the nionths of January and harbor and anchored for the winter. We prospected for gold February, 1904, present anew a large increase in the clepres- for some two months. sion, and the values of intensity observed during these months On the 3Uth of March the chinook winds set in and the seem even lower than at the beginning of 1903. Thus the snow melted with great rapidity. When we entered the island month of February, 1904, gives values diminished by more the only snow we saw was on the coast. East of us was a than 30 per cent. The depression ends in the same month, in mountain of rock, I should think 30 miles from the head of a manner as abrupt as its beginning. the bay- It appeared 10,000 feet high, and was bare when we 8. Drcration of inxolafzoti i)i hoicrs aiid total piiarltzty of hrnt iii came in sight of it; but in a couple of weeks it was covered gram calories at Vanxito tlriritiy the yam1203, 1.W4. ntjd 1XG.- with snow. This profound perturbation in the intensity of solar radiation After the chinook mind, which appeared to come from the as it reaches the surface of the earth may have given rise to Bouthwest-we took it for granted it \vas the Japan current important meteorological results. The question as to the in- had blown for twenty-four hours it seemed as if the water was fluence mill be of the highest interest and will necessitate leaping from every mountain top. The roar of it was some- special research, altho the problem presents great difionlties thing like Niagara, tho not SO deep, as the water was scattered, and complications. We acld that the study of this question EO to speak. has been already begun in an iniportant memoir, by S. P. On the 1st of April we raiseel anchor, and at 4 p. m. were in -~ __~ -_ ~~ Langley, published in the Astrophysical Journal.Is - ______ ~~ llWe can uot here enter into the details of these calculations. See G. 13 8. P. Langley. On a possible rariation of the solar radiation, and 1906. Chap. SI, pp. 167-166. its probable effect on terrestrial temperature. (Astrophysical Journal, '5 Ac~orcliugLI) the mean '' montlily values of the intensity in 1901- vol. 19, pp. 305-331.) 1905. See C;. 1906; Chap. XI, pp. 172-1715. Unauthenticated | Downloaded 09/23/21 01:31 PM UTC 176 MONTHLP WEATHER REVIEW. APRIL,1907 the open sea, bound for Puget Sound. The weather did not To the best of my knowledge, the name *'chinook " is applied to two very different sorts of winds. I believe it was originally applied to a seem as warm when we reached the outside, and I do not warm, moist southwest wind at stations near the coasts of Oregon, remember exactly its temperature; but it was not nearly as Washington, and British Columbia, which was supposed to blow from cold as when we were on the way up, in January. the region where the Chinook Indians lived, or to be in some other way associated with them. Quite Independently of this use of the word, it THE "DRY" CHINOOK IN BRITISH COLUMBIA. was applied by settlers in the west of Montana to a warm, dry wind descending the Rocky Mountain slope. Some thought that it blew from By R. T. GRASsHaM. Dated Keithley Creek, B. C., March 5, 1907. the chinook region of the Pacific coast, others simply said that it was I am living at a stoc.k ranch in the Bonaparte Valley-which as warm as the chinook winds of the Pacific coast. However, in some lies about midway between the Cascade and Gold Ranges and way this application of the name to a warm, dry wind descending the mouutain in clear weather has become so geueral that its original appli- the Rocky Mountains-north of Ashcroft, on the line of the cation to a moist, southwest wind has been almost lost sight of. Canadian Pacific Railway.' Our district is known as the " dry The discussion in reference to the winds of Deceniber 22, 1906, hinges belt ". Very little or no rain falls during the spring or sum- upon the definition of a chinook wind. If it means the wet chinook of mer. We depend upon irrigation for our crops and hay, and the coast of British Columbia, then its temperature and moisture are due to the fact that it has just arrived from the Pacific Ocean, laden with my experience of the chinook is as follows: moisture which is condensed into cloud and rain as the wind rises over After having a cold snap of zero weather, with a foot of the coast rauges. The *Japan current is too far to the west to have any snow on the flats and hillsides-bright clear weather-there particular influence on either temperature or moisture. On that par- comes a change; heavy dark cloucls loom up from the west ticular clatr, Drceiulber 22, an area of low pressure was mest of Vancouver Island, anal, whatex er the local winds uiay have been, there must have and southwest, acconipaniecl by a very strong win(l--nt tinies nerd movruirnt of tlia atmosphere from the Pacifiv west of one might call it a gale.